Evaluating an entanglement measure \(\mathcal {E}(\rho )\)  is — in such cases where this is even possible at all — a demanding task, as it requires the full knowledge of \(\rho \) . To circumvent this requirement, which in most experimental situations is just impossible to fulfill, methods have been developed to at least lower bound interesting measures from limited information on \(\rho \)  [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}. Although some of these have been applied with extraordinary success in optical experiments (see Ref. [14]} for a recent review), finding an approach suitable to platforms where the number of accessible
observables is particularly limited (e.g.  collective properties) remains extremely challenging.
